抄録
Local thermotherapy reduces mental stress, but its mechanisms are still poorly understood. In this study, we investigated effects of a heat- and steam-generating sheet (HSG sheet) on the cerebral hemodynamics and autonomic nervous activity using near infrared spectroscopy (NIRS) and electrocardiograms (ECGs). Ten healthy young subjects (mean age= 26.2) participated in this experiment. Each experimental session consisted of 4 phases; 1) application of HSG sheet or simple eye-mask (control) to the eye region for 120 sec, 2) rest for 60 sec, 3) mental arithmetic for 60 sec, and 4) rest for 120 sec. Each subject received 5 sessions. During the sessions following parameters were monitored; changes in brain oxygenated-Hb concentration (oxy-Hb), high frequency (HF) and low frequency (LF) components of heart rate variability (HRV). The results indicated that the HSG sheet decreased oxy-Hb concentration in the prefrontal cortex, while it increased hemodymamic responses to mental arithmetic. Furthermore, parasympathetic activity increased while sympathetic activity decreased. These results suggest that the application of the HSG sheet to the eye region induced relaxation while it increased activity of the prefrontal cortex during mental works. [J Physiol Sci. 2008;58 Suppl:S172]
